When the West Nile Virus hit New York City in 1999, it claimed thousands of lives before spreading to other parts of the country, Canada and South America. In this increasingly connected and globalized world, diseases know no borders.
“The effect of globalization on infectious diseases is not being addressed by public health agencies anywhere,” said Duane Gubler, Director of the Program on Emerging Infectious Diseases at the Duke-National University of Singapore Graduate Medical School. “Unless it is addressed, we are going to continue to see epidemics of disease.”
In his keynote address at the Mosquito Biology and Biotechnology Conference at Duke this week, Gubler identified globalization as the single greatest challenge ahead as policymakers, researchers and public health officials try to control the spread of mosquito-borne diseases, like malaria and dengue fever.
Mosquito control has been an issue for decades, which Gubler believes is a history of failure since a worldwide malaria eradication program in the 1950s and 60s was disbanded, although it was largely successful. There was mounting political pressure to end the program after it was determined that DDT insecticide spray was harmful for the environment. As a result, the number of reported malaria cases spiked in various parts of the world, such as in Sri Lanka and India.
“Success breeds failure. We began to change the way we dealt with vector-borne diseases in the 1970s and 80s, what I like to call reactive control,” said Gubler. “What policy makers haven’t realized is that we have not eliminated these diseases, they have just been controlled. These diseases can and will return with vengeance.”
Recent data by The World Health Organization (WHO) shows 2.5 billion people, or two-fifths of the world’s population, are at risk of dengue fever. The disease is endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, Southeast Asia and the Western Pacific. The WHO also estimates that half of the world’s population is at risk of contracting malaria. In 2006, an estimated 247 million cases led to nearly 881,000 deaths.
Gubler said uncontrolled urbanization is complicating the problem today, since more people are living in poor conditions, often lacking adequate housing, piped water, sewer and waste management. He points out that these are ideal conditions for vector-borne, water-borne and food-borne diseases.
Gubler said effectively controlling vector-borne infectious diseases will require new technology, such as vaccines and antivirals. “We are making tremendous progress right now with vaccine development and drug development. They should be available in a few years,” said Gubler. “But I say that with guilt because we’ve been saying that for 30 years.”
In addition to new technologies, Gubler said it’s also important to “rebuild” public health with a proactive approach, including active laboratory-based early warning surveillance, case management and emergency response plans. Without it, he said, “we will continually wait for crises to occur, and we are always going to chase the fire.”
His infectious diseases research program in Singapore acts as the regional center for reference and research in the Asia-Pacific. The world-class center provides a U.S. Centers for Disease Control-like service to the region and builds capacity for early identification of new pathogens associated with disease with epidemic potential.
The Mosquito Biology and Biotechnology Conference was co-sponsored by the Duke Center for RNA Biology, the Institute for Genome Sciences and Policy, the Duke-NUS Graduate Medical School, the Burroughs Wellcome Fund and the Duke Global Health Institute.
